This invention relates to the high speed processing of documents, such as bank checks, and more particularly to a system and method for the high speed capturing, processing and storage of video image data from documents.
Documents such as bank checks are conventionally processed on a high speed reader/sorter which operates at a relatively high rate of speed on the order of about 2400 documents per minute. As the documents are processed through the reader/sorter, they are directed past an MICR reader which reads the magnetic ink characters on the documents The documents may also be directed past a microfilming station which microfilms both the front and back of the document The document is subsequently sorted into one of a number of output bins. In order to be sure that a legible image of the documents was captured on microfilm, it is necessary to hold the documents until the microfilm has been removed from the machine and developed, which could take as long as several days. However, in the case of bank checks, the financial institutions desire to process and forward the checks as quickly as possible to reduce the "float time". Consequently, the institutions are faced with releasing and forwarding the documents before they have obtained confirmation that the microfilming was successful, or holding the documents until the microfilm has been developed and incurring the added cost associated with this delay.
In order to overcome this problem, it has been proposed that the images on the documents be captured electronically rather than on microfilm, using video imaging technology. However, until now this approach has been technologically infeasible, due to the high volume of documents which must be processed and the large amount of video image data which is required to reproduce the images on the documents. Indeed, a recent study conducted by the Federal Reserve Bank concluded that the high speed capture and storage of video image data from bank checks is infeasible with existing video processing technology.
To obtain a high quality image, it is desirable to use a relatively high resolution, of for example, 240 pels per inch. In order to acceptably reproduce high contrast information such as numbers and signatures, as well as lower contrast information such as stamps and endorsements, the image needs to be captured at a high resolution in a number of levels of gray. To capture gray scale data for each side of a bank check at 240 pels per inch resolution and 256 gray levels would require 1.48 megabytes of video image data. Thus, to support the processing of checks at a feed rate of 40 documents per second would require the handling of approximately 118 megabytes of video image data per second.
It will thus be readily appreciated that the high speed processing of video image data from checks generates extremely high volumes of video image data. To be able to handle data at this high volume for a sustained period of time presents very significant technological challenges. Furthermore, since a document processing system employing this technology would need to provide storage for the check images over extended periods of time ranging from days to months or even years, significant challenges are also presented in providing a feasible way to store and retrieve massive amounts of video image data. While the image data could theoretically be stored on high speed mass data storage devices, such as magnetic DASD (Direct Access Storage Devices), the cost of this type of storage becomes prohibitive when considering the volume requirements for several months or even days worth of check image data. While optical storage devices are available which provide a lower cost alternative to mass data storage, the data transfer rates for the presently available optical data storage devices are considerably slower than the data transfer rate of magnetic DASD and would be incapable of accepting the video image data at the rate at which it is being generated, even if sophisticated and powerful data compression techniques are employed.
With the foregoing in mind it is an important object of the present invention to provide a system and method which enables the high speed capture, processing and storage of video image data from documents, such as bank checks.
A further object of the invention is to provide a system which can provide these capabilities at an economically feasible cost.
Because of the very high rate of data capture and storage, it is important to provide an assurance that the video image data which is being captured from the documents is of a quality sufficient for reproducing an acceptable quality image of the document. In particular, it would be desirable to have the capability to monitor image quality on a real time basis so that corrective actions can be taken immediately if the images captured from the documents are of unacceptable quality. Thus, still another object of the invention is to provide a system and method of the type described which provides for real time monitoring of image quality so that appropriate corrective action can be taken immediately if the image quality from the documents becomes unacceptable